Probe length

Auxiliary bearing and shaft vibration probe length (given by manufacturer)... 

Spatial resolution Cost Probe length Ease of use... 

In addition to probe length, other considerations in the selection of DNA probes include keeping the G-C composition to between 40 and 60%, and ensuring that no unusual base sequence is present, such as having no more than four at a stretch of a single base sequence (for example, -C-C-C-C-C-) or any other intraprobe complementary sequence that will reduce the specificity of the probe-sample target DNA interaction. 

A handheld thermocouple measurement device and an IR temperature sensor are very important to have for understanding the performance of the extruder. These devices have been discussed previously in this chapter. In many of the case studies presented later, the extrudate temperature was measured by immersing a handheld thermocouple probe into the extrudate. The entire probe length is immersed or draped in the extrudate to minimize heat conduction to cooler parts of the probe. The highest temperature measured is the reported value. If it is unsafe to measure the extrudate temperature using a handheld device, then an IR temperature sensor is used to estimate the discharge temperature. 

Fig. 4 Effect of spacer length on the mean hybridization intensity at five probe lengths. The basic single spacer unit had a length equivalent to a dT OND, so the scale is based on the equivalent number of nucleotides. Intensities were normalized to the intensity obtained using the 25mer probe with no added spacer [20]...

Figure 6.4 Tissue parameter effects on microdialysis sampling extraction efficiency(EE) using the published Bungay et al. model.42 (a) Parameters in graph (a) denote changes with diffusion coefficients combined with the following parameters probe length, L, 0.3 cm inner radius, ri 0.021 cm outer radius, r0,0.025 cm cannula radius, rcannuia, 0.0175 cm tissue sample volume fraction, ( )s, 0.2 membrane diffusion coefficient, Dm, 0.2Dd tissue sample diffusion coefficient, Ds = Dd/2.25 K,.p 1.0 min-1, Km 0.1 min-1. In vitro simulation sets the external tissue resistance, Rc to a value of zero, (b) Variation in tissue sample volume fraction, <(is, with all parameters used. Dd —5 x 10 6 cm2/s. (c) Variation in sum of external rate constants. All other parameters are as in (a) with Dd— 5 x 10-6 cm2/s.

Probe Length Chemical Steps Number of Possible Probes... 

Fig. 14. Relationship between local heat transfer coefficients and probe length (Bai et al, 1992). pm = 60 kg/m3.

Fig. 26. Comparison of profiles of heat transfer coefficient along probe length with model, Eq. (7) (Bai et al., 1991).

In the hybridzation of the labeled target to the immobilized probe and subsequent washing, two opposing forces need to be balanced—too stringent conditions develop low signals, whereas too unspecific hybridizations yield compressed ratios with little differential expression. An extensive analysis of the conditions is beyond the scope of this review, but the main parameters that must be considered are probe length. 

Hybridization Impinging on the rate and specificity of hybridization are the factors associated with stringency, especially temperature, salt concentration, and formamide concentration. Other factors include probe length and concentration. These parameters are empirically optimized. 

The actual glucose sensor (a platinum electrode covered by three membranes ceUulose acetate, nylon net with covalently Unked GOD, and a polycarbonate protective membrane) is located in a miniaturized waU-jet cell. The sensor exhibits excellent performance, with a linear range extending up to 27 mM, thanks to the microdialysis dilution effect which was estimated to be 1 10 for the probe length used and for the flow rate set by the instrumentation. Long-term stability tests revealed that the biosensor stiU maintains its initial activity after incubations of 4 weeks at 45°C, 11 weeks at 37°C, and 32 weeks at room temperature (see Table 12.2). From these results, a shelf life of more than 2 years at 2-8°C can be extrapolated [119]. 

In addition to probe concentration and availability, the length of the probe and the complexity of the nucleic acids affect hybridization rates. Rates are directly proportional to the square root of the probe length and inversely proportional to complexity, defined as the total number of base pairs present in nonrepeating sequences. Mismatches up to about 10% have little effect on hybridization rates. 

In Situ STM Hopping Current Dependence on Probe Length and Bias Voltage... 

A constant amount of probe ( 300 bases) is added, e.g., 3x10 at 10 cpm/p.g for other specific activities or probe lengths, the amount should be adjusted to maintain the same molarity. Standard RNase is as in Section 12.4.2.3. 

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